Hey shrekGKSprivacy!
This is Bradley, the programmer for the game. We used Unity's high definition rendering pipeline to get the lighting in the game just right, but we also wanted a pixel shader to go with the game. Unfortunately, it does not seem like the pixel shader is possible without weird workarounds which is what we did. The game essentially has a camera and a camera texture: the camera renders the normal game and the texture renders the game at a lower resolution giving it the pixel style we were looking for. This can cause some lag on older machines. We are looking into different ways of fixing this issue.
Thanks for the feedback!